package com.free.freemarker.utils;

public class DataUtil {

	/**
	 * 将原数组内容加到目标数据中,并返回目标数组
	 * 
	 * @param target
	 * @param source
	 * @param pos
	 * @return
	 */
	public static byte[] joinArray(byte[] target, byte[] source, int pos) {
		for (int i = 0; i < source.length; i++) {
			target[pos + i] = source[i];
		}
		return target;
	}

	public static void main(String[] args) {
        String str="192.168.1.125";
        byte[]source=str.getBytes();
        int length=source.length;
        System.out.println(length);
        for(int i=0,len=source.length;i<len;i++){
//        	System.out.println(source[i]);
        }
        
        byte[]target=new byte[16];
        for(int i=0,targetlength=target.length;i<targetlength;i++){
        	if(i<length){
        		target[i]=source[i];
        	}else{
        		target[i]=0;
        	}
        }
        System.out.println(new String(target));
        
      
	}

	/**
	 * 将一个单字节的byte转换成32位的int
	 * 
	 * @param b
	 *            byte
	 * @return convert result
	 */
	public static int unsignedByteToInt(byte b) {
		return (int) b & 0xFF;
	}

	/**
	 * 将一个单字节的Byte转换成十六进制的数
	 * 
	 * @param b
	 *            byte
	 * @return convert result
	 */
	public static String byteToHex(byte b) {
		int i = b & 0xFF;
		return Integer.toHexString(i);
	}

	/**
	 * 将一个4byte的数组转换成32位的int
	 * 
	 * @param buf
	 *            bytes buffer
	 * @param pos 中开始转换的位置
	 * @return convert result
	 */
	public static long unsigned4BytesToInt(byte[] buf, int pos) {
		int firstByte = 0;
		int secondByte = 0;
		int thirdByte = 0;
		int fourthByte = 0;
		int index = pos;
		firstByte = (0x000000FF & ((int) buf[index]));
		secondByte = (0x000000FF & ((int) buf[index + 1]));
		thirdByte = (0x000000FF & ((int) buf[index + 2]));
		fourthByte = (0x000000FF & ((int) buf[index + 3]));
		index = index + 4;
		return ((long) (firstByte << 24 | secondByte << 16 | thirdByte << 8 | fourthByte)) & 0xFFFFFFFFL;
	}

	/**
	 * 将16位的short转换成byte数组
	 * 
	 * @param s
	 *            short
	 * @return byte[] 长度为2
	 * */
	// public static byte[] shortToByteArray(short s) {
	// byte[] targets = new byte[2];
	// for (int i = 0; i < 2; i++) {
	// int offset = (targets.length - 1 - i) * 8;
	// targets[i] = (byte) ((s >>> offset) & 0xff);
	// }
	// return targets;
	// }

	/**
	 * 将32位整数转换成长度为4的byte数组
	 * 
	 * @param s
	 *            int
	 * @return byte[]
	 * */
	// public static byte[] intToByteArray(int s) {
	// byte[] targets = new byte[2];
	// for (int i = 0; i < 4; i++) {
	// int offset = (targets.length - 1 - i) * 8;
	// targets[i] = (byte) ((s >>> offset) & 0xff);
	// }
	// return targets;
	// }

	/** 32位int转byte[] */
	public static byte[] int2byte(int res) {
		byte[] targets = new byte[4];
		targets[0] = (byte) (res & 0xff);// 最低位
		targets[1] = (byte) ((res >> 8) & 0xff);// 次低位
		targets[2] = (byte) ((res >> 16) & 0xff);// 次高位
		targets[3] = (byte) (res >>> 24);// 最高位,无符号右移。
		return targets;
	}

	/** 8位int转byte[] */
	public static byte int2byte8(int res) {
		byte targets = (byte) (res & 0xff);// 最低位
		// targets[1] = (byte) ((res >> 8) & 0xff);// 次低位
		// targets[2] = (byte) ((res >> 16) & 0xff);// 次高位
		// targets[3] = (byte) (res >>> 24);// 最高位,无符号右移。
		return targets;
	}

	/**
	 * 将长度为2的byte数组转换为16位int
	 * 
	 * @param res
	 *            byte[]
	 * @return int
	 * */
	public static int byte2int(byte[] res) {
		// res = InversionByte(res);
		// 一个byte数据左移24位变成0x??000000，再右移8位变成0x00??0000
		int targets = (res[0] & 0xff) | ((res[1] << 8) & 0xff00); // | 表示安位或
		return targets;
	}

	/**
	 * short 转为 byte数组
	 * 
	 * @param s
	 * @return
	 */
	public static byte[] short2Byte(short s) {
		byte[] b = new byte[2];
		b[1] = (byte) (s >> 8);
		b[0] = (byte) (s >> 0);
		return b;
	}

	/**
	 * byte数组转为short
	 * 
	 * @param b
	 * @return
	 */
	public static short byte2Short(byte[] b) {
		return (short) ((b[1] << 8) | b[0] & 0xff);
	}

	/**
	 * long to byte[]
	 * 
	 * @param s
	 *            long
	 * @return byte[]
	 * */
	public static byte[] longToByteArray(long s) {
		byte[] targets = new byte[8];
		for (int i = 0; i < 8; i++) {
			int offset = (targets.length - 1 - i) * 8;
			targets[i] = (byte) ((s >>> offset) & 0xff);
		}
		return targets;
	}

}
